Field of the Invention
Embodiments of the present invention generally relate to display screens, and more specifically, to methods of dynamically controlling power consumed by and brightness of display screens.
Description of the Related Art
Electronic display systems are commonly used to display information from computers and other sources. Typical display systems range in size from small displays used in mobile devices to very large displays, such as tiled displays, that are used to display images to thousands of viewers at one time. Reduced power consumption is one desirable feature of such displays, both because of the long-term energy savings provided to the user and because of the reduced cost and complexity of installation associated with systems having lower power requirements.
Some technologies for electronic display systems, such as laser phosphor displays (LPDs) and organic light-emitting diodes (OLEDs), are able to significantly reduce power consumption by using a “color adding” approach to produce color at each pixel on the viewing surface. Specifically, red, green, and blue light energy is generated at a given pixel to produce the desired brightness and hue for that pixel. Thus, the power use of LPDs, OLED displays, and the like is proportional to the total optical energy produced by the viewing surface of the display. This is in contrast to display systems that produce color at each pixel on the viewing surface by selectively filtering or blocking light of different colors, such as a digital light processing (DLP) display. In such systems, white light source, such as an incandescent bulb, is set at full intensity at all times in such a display system. As such, there is no reduction in power consumption when the system is producing darker images or images that do not require all three colors.
When averaged over a large number of images or over a relatively long time interval, the power consumption of LPDs, OLED-based display screens, and other display systems that use a color-adding approach to produce color can be substantially less than that of other display technologies. However, such display systems provide less energy savings when most or all of a particular image being displayed is relatively bright. Thus, when displaying brighter images, less energy savings are provided to the user by color-adding display systems.
In addition, in a tiled display system, power usage by the tiled display system may exceed available power, when they are displaying bright images. This may be true even in tiled systems employing LPDs. Upgrading the power supply to such a system may be an option, but it can be costly. The other option is to recalibrate the system to a lower maximum power level but this affects the quality of low brightness images and the dynamic range.
As the foregoing illustrates, there is a need in the art for a method of displaying an image with an electronic display device while staying within the maximum available power.